The nucleus is the largest and perhaps most complex organelle of the eukaryotic cell. Studies of cellular and developmental regulation, oncogenesis, and viral infection increasingly converge upon nuclear localization and direction to an appropriate intranuclear address as important points of regulation. Although the molecular details of individual nuclear functions have been worked out in vitro, only recently have exciting studies shown the dependence of these functions on particular structures within the nucleus. Important questions include how chromosomes are constructed and organized, the mechanism of nuclear transport, and the mechanism of assembly and disassembly of the nucleus at mitosis. Others include determining the organization and function of nuclear structures such as the nuclear matrix and the nucleolus. Lastly, exciting questions focus on the molecular composition and roles of an increasing number of new and unexpected intranuclear organelles, as well as recently discovered intranuclear tracks along which mRNA and protein molecules appear to move in a directed manner. The goal of the meeting is to bring together specialists on all aspects of nuclear structure and function in order to assemble a three-dimensional, functional view of the nucleus. SESSION TOPICS: 1. The Nuclear Envelope: A Structural View 2. The Mechanism of Nuclear transport: Import, Export, Cytosolic Factors 3. Assembly & Disassembly of the Nucleus in the Cell Cycle 4. Chromatin & Chromosomes: Organization, Regulation of Transcription, and Chromatin 5. Centromeres and Telomeres 6. DNA Replication: Basics, Relationship to Higher Order Nuclear Structures 7. Nuclear Domains and Addresses: The Nucleolus and Multiple New Intranuclear "Organelles" 8. The Nuclear Matrix: Structure and Function 9. RNA Splicing and Alternate Splicing: Basics, Supramolecular Nuclear Organelles for Splicing 10. mRNA Export